ClothesThere are 328 different swimsuits in the game.
DevelopmentAccording to lead designer Itagaki, Dead or Alive: Xtreme Beach Volleyball was originally the concept for a minigame in DOA2: Hardcore.
NudityThough the game says there is nudity in the game, the only actual nudity seen is in the opening cutscene. You can't see anything, though, due to the lighting.
Information also contributed by Link amza